Next door to Berkeley's Public Library, locals gathered on the cordoned-off area from early morning to try and make sense of the tragedy.

Shock and anger filled the roads surrounding 2020 Kittredge Street as news that six students had fallen to their deaths from one of only two front-facing balconies on the Library Gardens complex began to spread.

A handful of red plastic beer cups that lay amongst small piles of concrete rubble were a grim reminder that the students were celebrating a 21st birthday when the horrific incident took place.

But no amount of yellow police tape could prepare onlookers for the view of the railings of the lone fourth-floor balcony perching on top of the one below, after apparently making an almost clean breakaway from both the wall and the glass French doors.

Around the corner from the media swarm in a Starbucks, two Irish students politely declined to comment to reporters after huddling over their iPhones and texting and talking to family members to assure them they were okay.

One of the stricken young men said: "I knew them, sorry - I just don't want to speak at all."

DCU student Connor Mulligan, from Dundalk, who arrived here on his J1 visa on May 26, said he was worried people would try to blame the accident on alcohol.

"We were actually at a baseball game last night and got off the BART (mass transit system) at about 12, and we walked this side of the road back home about half-an-hour or 45 minutes before it happened," he added.

"We didn't hear a party or see anyone on the balcony. We live about a 10-minute walk away, up near the college. We heard the helicopters going over the house at about 6am, so it was pretty crazy.

"It will be very hard for the people that are close to them - I'd say that a lot of them will go home."

Jennifer James, who originally comes from Waterford but has lived in nearby Oakland for 15 years, arrived at approximately 9.30am with a friend to offer comfort, support and a place to stay to any students affected by the tragedy.

After laying flowers on the ground, she said: "It's shocking. My nephew is going into second year in college, so it could have been him - it's his age group, his peers.

"It's very upsetting because we know how it feels to be so far away and to live 6,000 miles away from your family. I'm thinking about the kids who survived and don't have any support here."

"I think the allure of Berkeley is because housing is expensive and scarce in San Francisco. It is a student town and I know a lot of these students are working up at the university because my daughter goes to summer camp up there."

By 11.30am, yet more grief-stricken Irish students had arrived on the street to pay their respects. Approximately 10 young women shed silent tears as they made their way home.

One, who asked not to be named, said: "We've heard rumours about names but don't know for sure yet. I'm just praying that I don't know any of them."

Just weeks after moving here from her native France to begin studying at the nearby University of California, Berkeley, in August, Alison Vayne said she felt a close connection to the victims.

She added: "I looked at apartments around here and I stopped at Library Gardens, so I'm very shocked about what happened here. The price put me off - they were very expensive. I think for one bedroom it was close to $2,000 a month. That's why I'm shocked about what happened.

"I'm just shocked and I'm sad. They were probably very young and just starting out in life. To have an accident like this and have people die is just shocking, really."

Construction worker Morgan Subrayan, who has lived in the area for 26 years, said he believed dry rot was responsible for the incident, which has shocked locals.

Asked for his reaction, he said: "Mad and upset. It's a five-year old building.

"It's so sad. Six of them died, and it's just ridiculous. Kids, college students at university, they're going to have fun, they're going to drink, but why should the structure come down? I'm sure they're going to find some alcohol - you see all the cups down there - but what has alcohol got to do with the structure?"

Mr Subrayan added he believed it was irrelevant how many people had been on the balcony at the time.

"It's dry rot," he added. "It's a five-year-old building during a drought. We don't know what kind of wood they used.

"The city has to get involved and the builder has to get involved. I think they have to change the rules so anything above two or three storeys has to have a solid iron beam. The laws are pretty strict, but I think lately there have been many buildings coming up."

Another long-time local added: "I'm in shock. I don't think six people have died in Berkeley all at once in my memory."

Ninette Lewis, from Oakland, added: "We're in the neighbourhood and I didn't realise how close it was. You never know when your time is going to come. You might be out having a good time."